Blog Featured Image Duplicating

I have just started a position at a small company and am required to regularly add blog posts to the website using WordPress. This is something I’ve not done before and I can’t figure out why when I set a featured image for the blog post, it duplicates as some sort of banner at the top of the page? This is the case for each blog post. I tried removing the featured image and it just displayed an orange block where the featured image would be and a different image across the top of the page.

The page I need help with: [log in to see the link]